Hybrid utility vehicle

ABSTRACT

A hybrid vehicle may be a series hybrid or a parallel hybrid vehicle. One embodiment of a parallel hybrid vehicle includes an engine, a transmission coupled to the engine, a front drive coupled to the transmission through a prop shaft, a rear drive coupled to the transmission, a traction motor drivingly coupled to the prop shaft, and a battery to operate the traction motor.

FIELD OF THE DISCLOSURE

The present application relates to a utility vehicle and, moreparticularly, a hybrid utility vehicle configured to operate in variousdrive modes.

BACKGROUND OF THE DISCLOSURE

Electric vehicles are known to have at least one battery pack which maybe operably coupled to an electric motor for charging the battery packand/or for driving the wheels of the vehicle. A hybrid vehicle, however,has both an electric motor and an internal combustion engine. In oneembodiment of a hybrid vehicle, the engine and the battery packs operatein series, meaning that the battery packs provide the power or energyfor driving the wheels and the engine operates to charge the batterypacks. Alternatively, in another embodiment, a hybrid vehicle may be aparallel hybrid vehicle, meaning that the battery packs provide thepower or energy to drive either the front or rear wheels but the engineprovides the motive power to drive the other set of wheels.

SUMMARY OF THE DISCLOSURE

In one embodiment, a parallel hybrid power train comprises an engine, anelectric motor/generator, a transmission having an input shaft, at leasta second shaft drivingly coupled to the input shaft, the engine and theelectric motor/generator being coupled to one of the input or secondshafts, and at least a first output; and a final drive assembly operablycoupled to the first output, the final drive assembly being profiled fordriving ground engaging members of a vehicle.

The parallel hybrid power train may comprise a silent mode wherein theelectric motor/generator operates to drive the transmission output. Theparallel hybrid power train may also allow the engine driven generatorto charge the battery. In this embodiment, the parallel hybrid powertrain comprises a charge at rest mode wherein the engine is run to onlycharge the batteries through the engine driven motor/generator.

The parallel hybrid power train may also comprise a full performancemode wherein the motor/generator and engine are both operated to addtorque to the transmission output.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features of this invention, and the mannerof attaining them, will become more apparent and the invention itselfwill be better understood by reference to the following description ofembodiments of the invention taken in conjunction with the accompanyingdrawings, where:

FIG. 1 is a front left perspective view of a series hybrid utilityvehicle of the present disclosure;

FIG. 2 is a rear right perspective view of a first embodiment of apowertrain assembly of the series hybrid utility vehicle of the presentdisclosure;

FIG. 3 is a rear left perspective view of a driveline of the serieshybrid utility vehicle of FIG. 2;

FIG. 4 is a rear right fragmented perspective view of the drivetrain ofFIG. 2 in the frame;

FIG. 5 is a rear left fragmented perspective view of the drivetrain ofFIG. 4;

FIG. 6 is a right side view of the drive train of FIG. 2;

FIG. 7 is an exploded view of a portion of the power train with themotor/generator exploded away from the transmission;

FIG. 7A is an enlarged portion of the coupling mechanism shown in FIG.7;

FIG. 8 is an exploded view showing the motor/generator and the mountingbracket;

FIG. 9 is a partial cross-sectional view showing the coupling betweenthe motor/generator and the transmission;

FIG. 10 is a cross-sectional view through lines 10-10 of FIG. 6illustrating the power flow between various components of the hybridutility vehicle of FIG. 2 in various drive modes;

FIG. 10A is a view similar to that of FIG. 10, showing the drive modewith the engine drive only in high gear;

FIG. 10B is a view similar to that of FIG. 10, showing the drive modewith the engine and motor drive in low gear defining a“Charge-and-Drive” drive mode;

FIG. 10C is a view similar to that of FIG. 10, showing a fullperformance drive mode with the engine and motor/generator drive in lowgear;

FIG. 10D is a view similar to that of FIG. 10, showing the drive modewith the motor drive only in low gear;

FIG. 10E is a view similar to that of FIG. 10, showing a“Charge-at-Rest” drive mode;

FIG. 11 is a rear right perspective view of a second embodiment of apowertrain assembly of the series hybrid utility vehicle of the presentdisclosure;

FIG. 12 is a rear right fragmented perspective view of the drivetrain ofFIG. 11 in the frame;

FIG. 13 is a right side view of the drive train of FIG. 11;

FIG. 14 is a front left perspective view showing the motor coupled tothe transmission for the embodiment of FIG. 11;

FIG. 15 is a rear right perspective view showing the motor coupled tothe transmission for the embodiment of FIG. 11;

FIG. 16 is a cross-sectional view through lines 16-16 of FIG. 13illustrating the power flow between various components of the hybridutility vehicle of FIG. 11 in various drive modes;

FIG. 16A is a view similar to that of FIG. 16, showing a“Charge-and-Drive” drive mode in high gear;

FIG. 16B is a view similar to that of FIG. 16, showing a“Charge-and-Drive” drive mode in low gear;

FIG. 16B is a view similar to that of FIG. 16, showing the drive modewith the engine drive only in low gear;

FIG. 16C is a view similar to that of FIG. 16, showing a fullperformance drive mode with the engine and motor drive in low gear;

FIG. 16D is a view similar to that of FIG. 16, showing a fullperformance drive mode with the engine and motor drive in low gear;

FIG. 16E is a view similar to that of FIG. 16, showing the drive modewith the motor drive only;

FIG. 16F is a view similar to that of FIG. 16, showing a“Charge-at-Rest” drive mode in low gear;

FIG. 16G is a view similar to that of FIG. 16, showing a“Charge-at-Rest” drive mode in high gear;

FIG. 17 is a schematic view of a controls system of the vehicle of FIG.1;

FIG. 18 is a controls diagram of a first drive or control mode foroperating the vehicle of FIG. 1;

FIG. 19 is a controls diagram of a second drive or control mode foroperating the vehicle of FIG. 1; and

FIG. 20 is a controls diagram of a third drive or control mode foroperating the vehicle of FIG. 1.

Corresponding reference characters indicate corresponding partsthroughout the several views. Although the drawings representembodiments of the present invention, the drawings are not necessarilyto scale and certain features may be exaggerated in order to betterillustrate and explain the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The embodiments disclosed below are not intended to be exhaustive or tolimit the invention to the precise forms disclosed in the followingdetailed description. Rather, the embodiments are chosen and describedso that others skilled in the art may utilize their teachings. While thepresent disclosure is primarily directed to a utility vehicle, it shouldbe understood that the features disclosed herein may have application toother types of vehicles such as other all-terrain vehicles, motorcycles,snowmobiles, and golf carts.

Referring first to FIGS. 1-3, an illustrative embodiment of a hybridutility vehicle 10 is shown, and includes ground engaging members,including front ground engaging members 12 and rear ground engagingmembers 14, a powertrain assembly 16 (FIG. 2), a frame 20, a pluralityof body panels 22 coupled to frame 20, a front suspension assembly 24, arear suspension assembly 26, and a rear cargo area 28. In oneembodiment, one or more ground engaging members 12, 14 may be replacedwith tracks, such as the PROSPECTOR II tracks available from PolarisIndustries, Inc. located at 2100 Highway 55 in Medina, Minn. 55340, ornon-pneumatic tires as disclosed in any of U.S. Pat. No. 8,109,308,filed on Mar. 26, 2008 (Attorney Docket No. PLR-09-25369.02P); U.S. Pat.No. 8,176,957, filed on Jul. 20, 2009 (Attorney Docket No.PLR-09-25371.01P); and U.S. Pat. No. 9,108,470, filed on Nov. 17, 2010(Attorney Docket No. PLR-09-25375.03P); and U.S. Patent ApplicationPublication No. 2013/0240272, filed on Mar. 13, 2013 (Attorney DocketNo. PLR-09-25201.02P), the complete disclosures of which are expresslyincorporated by reference herein. Vehicle 10 may be referred to as autility vehicle (“UV”), an all-terrain vehicle (“ATV”), or aside-by-side vehicle (“SxS”) and is configured for travel over variousterrains or surfaces. Furthermore, vehicle may be similar to thatdisclosed in U.S. Patent application publication 20170355259, thecomplete disclosure of which is expressly incorporated by referenceherein. More particularly, vehicle 10 may be configured for military,industrial, agricultural, or recreational applications.

Powertrain assembly 16 is operably supported on frame 20 and isdrivingly connected to one or more of ground engaging members 12, 14. Asshown in FIGS. 2-5, powertrain assembly 16 may include an engine 30(FIG. 2) and a transmission, for example a continuously variabletransmission (“CVT”) 32 (FIG. 3) and/or a shiftable transmission 34.Transmission 34 is shown as a transaxle which includes a combinationshiftable transmission and final drive. However, the transmission andfinal drive may be separated and coupled together as shown in U.S. Pat.No. 8,596,405. Engine 30 may be a fuel-burning internal combustionengine, however, any engine assembly may be contemplated, such ashybrid, fuel cell, or electric engines or units. In one embodiment,powertrain assembly 16 includes a turbocharger (not shown) and engine 30is a diesel internal combustion engine. Additional details of CVT 32 maybe disclosed in U.S. Pat. Nos. 3,861,229; 6,120,399; 6,176,7966,860,826; and 6,938,508, the complete disclosures of which areexpressly incorporated by reference herein.

As shown in FIG. 1, front suspension assembly 24 and rear suspensionassembly 26 may be similar to that described in U.S. Pat. No. 7,819,220,filed Jul. 28, 2006, the complete disclosure of which is expresslyincorporated by reference herein. Alternatively, rear suspensionassembly 26 may be as shown and described in U.S. Patent ApplicationPublication No. 2012/0031693, filed Aug. 3, 2010, titled “SIDE-BY-SIDEATV, the complete disclosure of which is expressly incorporated byreference herein.

Referring again to FIG. 1, vehicle 10 includes an operator area 40supported by frame 20, and which includes seating for at least anoperator and a passenger. Illustratively, one embodiment of vehicle 10includes three seats, including an operator seat 42, a front passengerseat 44, and a middle seat 46. Operator seat 42 includes a seat bottomand a seat back. Similarly, front passenger seats 44 and 46 include aseat bottom and a seat back.

As described above, vehicle 10 includes frame 20 supported by groundengaging members 12, 14. Illustratively, rear frame portion 48 (FIGS. 4and 5) supports powertrain assembly 16 and rear cargo area 28. Vehicle10 also comprises an overhead or upper frame portion 50. Upper frameportion 50 is coupled to frame 20 and cooperates with operator area 40to define a cab of vehicle 10. Additional details of vehicle 10 may bedisclosed in U.S. Pat. No. 8,998,253, filed Mar. 28, 2013, the completedisclosure of which is expressly incorporated by reference herein.

Referring to FIGS. 2 and 3, in one embodiment, vehicle 10 is a serieshybrid utility vehicle configured for engine and electrical operation.Vehicle 10 includes a motor/generator 60 operably coupled totransmission 34 to provide input power to the transmission as furtherdescribed herein. Vehicle 10 further includes a plurality of batteries70 for driving motor/generator 60 and which can be charged by the engine30 as further described herein. While only one battery 70 is shown, itshould be understood that multiple batteries may be coupled together ora battery pack may be provided. An engine control unit 74 is provided toassist in the control of the motor/generator 60. As shown best in FIG.3, vehicle 10 further includes a transmission rear output at 78 forcoupling to half shafts (not shown) to drive the rear wheels 14, and afront output 80 which couples to a drive shaft 82 which in turn iscoupled to a front final drive 84 having a front output at 86. It shouldbe appreciated that half shafts (not shown) are coupled to the frontwheels 12 and driven by output at 86.

With reference again to FIGS. 4 and 5, powertrain 16 is shown mountedwithin rear frame portion 48. As shown, rear frame portion 48 includes alower frame portion 90 which supports engine 30 and transaxle 34. Rearframe portion 48 further includes upstanding posts 92 coupled tolongitudinal rails 94 which support rearwardly extending frame tubes 96which enclose the powertrain 16 yet provide support for utility bed 28(FIG. 1). A seat support 98 is provided which is supported bylongitudinal frame tubes 94 and enclose battery 70 and engine controlunit 74. Seat support 94 supports the operator and passenger seats 42,44, 46.

With reference now to FIGS. 6-8, the mounting of the motor/generator 60and the coupling to the transaxle 34 will be described in greaterdetail. As shown best in FIG. 7, transaxle 34 includes an upper inputshaft 100 which is internally split to provide a shaft portion 102 andshaft portion 104. Shaft portion 102 receives power input from CVT 32whereas shaft portion 104 receives power input from motor/generator 60.As is known, engine 30 would drive a drive clutch of CVT 32 whichinternally drives a driven clutch of CVT 32, and the driven clutch ofCVT 32 would couple to the shaft portion 102. The hybrid drive aspectwill now be described in greater detail herein, with a first discussionregarding the mounting of the motor/generator 60 to the transmission 34.

With reference now to FIGS. 7, 7A and 8, transaxle 34 includes threethreaded posts or studs 110 (FIG. 7A) extending outwardly from a housing112 of the transaxle on the same side of the transaxle as shaft portion104. As described herein, studs 110 correspond with lock nuts 114. Asshown best in FIG. 7, a mounting assembly 120 is provided for mountingmotor/generator 60 to the transaxle 34. As shown in FIGS. 7 and 7A,mounting assembly 120 includes a spacer 124, lock nuts 126 and 128,inner bracket 130, bearing 132 and outer bracket 134. Spacer 124includes a threaded portion 140, a hexagonal portion 142 and a threadedportion 144. It should be appreciated that the transaxle housing 112includes a threaded opening 146 positioned around shaft portion 104,which threadedly receives threaded portion 140 of spacer 124. Spacer 124also includes an opening at 148 which is larger than shaft portion 104such that when spacer 124 is threaded into opening 146, shaft portion104 extends through spacer 124 but does not contact spacer 124. Lock nut126 is threaded onto threaded portion 144 of spacer 124 and may float inorder to define the lateral position of inner bracket 130 as describedherein.

Once coupler 124 is attached to threaded opening 146, inner bracket 130may be mounted to transaxle 34. As shown best in FIG. 7A, inner bracket130 includes three apertures at 150 which correspond with threaded posts110 such that inner bracket 130 may be positioned over transaxle 34. Itshould also be appreciated that lock washer 126 is moved to an inwardmost position to allow the positioning of inner bracket 130. Innerbracket 130 includes an opening at 160 which includes an enlargeddiameter portion 162, reduced diameter portion 164, shoulder 166 andopening 168. It should be appreciated that threaded portion 144 ofspacer 124 may be received through opening 168 of inner bracket 130 andthat lock washer 128 is positioned through opening 162 and is threadablyreceived on the threaded portion 144 which protrudes through opening168. Bearing 132 is then received within the diameter portion 162 ofopening 160. This can be seen best in the cross-sectional view of FIG.9. With bearing 132 positioned within diameter portion 162, shaft 104 iscarried within the bearing 132. Lock nuts 126 and 128 are tightenedagainst bracket 130, as shown best in FIG. 9. Lock nuts 114 are alsocoupled to the threaded studs 110, which couples the inner bracket 130to the transmission 34.

Outer bracket 134 is shown best in FIG. 8, and includes a plurality ofrecessed openings 170 which align with threaded bosses 172 onmotor/generator 60 to receive cap screws 174 therethrough to couple theouter bracket 134 to the motor/generator 60. Outer bracket 134 furtherincludes openings 180 which align with threaded openings 182 onmotor/generator 60 and receive fasteners 184 therethrough to furthercouple outer bracket 134 to motor/generator 60. The two brackets 130,134 are now aligned which also aligns shaft portion 104 with outputshaft 190 of motor/generator 60. Shaft 190 is internally splined whichcouples with shaft portion 104. Brackets 130 and 134 may then be coupledtogether by way of fasteners 200 extending through apertures 202 ofbracket 130 and into threaded openings 204 of outer bracket 134. Asshown in FIG. 7, fasteners 210 may also be received through apertures212 of bracket 134 and into threaded engagement with threaded apertures214 of bracket 130. Thus as coupled together as described above, eitherthe motor/generator 60 or CVT 32 may provide input power to thetransaxle through corresponding input shafts 104, 102. This providesmultiple modes of operation of the hybrid vehicle as described herein.

With reference now to FIG. 10, the inner gearing of the transaxle 34will be described in greater detail. As shown, shaft portions 102 and104 are separated but may be coupled together by way of coupler 220. Theend of shaft 102 has a splined portion at 222 and the end of shaft 104has a splined portion 224, where both splined portions 222 and 224extend into a splined coupling portion of coupler 220. Coupler 220 islaterally movable along the direction of arrow designated as 226 suchthat when in the position shown in FIG. 10, the two. 104 are coupledtogether and act as one. If the coupler 220 is moved to the left asviewed in FIG. 10, shaft portion 104 is decoupled from shaft portion 102whereas when the coupler is moved to the right as viewed in FIG. 10,shaft portion 102 is decoupled from shaft portion 104. As shown, shaftportion 102 includes a gear at 230 and shaft portion 104 includes a gearat 232. An intermediate shaft 240 is provided which provides a gear 242in meshing engagement with gear 230 and a gear 244 in meshing engagementwith gear 232. Shaft 240 further includes a gear 246. As shown in FIG.10, gear 242 may be laterally movable in the direction of arrow 248, forexample by way of a dog clutch (not shown) whereby gear 242 may be movedinto and out of meshing engagement with gear 230. In a similar manner,and as shown in FIG. 10, gear 244 may be laterally movable in thedirection of arrow 249, for example by way of a dog clutch (not shown)whereby gear 244 may be moved into and out of meshing engagement withgear 232.

A lower shaft 250 is provided having a gear 252 in meshing engagementwith gear 246 and shaft 250 includes a gear 254 in meshing engagementwith a gear 256. It should be appreciated that gear 256 provides theoutput to transaxle outputs 78 and 80 (FIG. 3). It should also beappreciated that a combination of gears 232 and 244 represent a lowgear, that is a high torque gear, whereas the combination of gears 230and 242 represent a high gear, that is a higher speed gear. Thus withthe coupling as described, multiple modes of operation of the transaxleare available. For example as shown in FIG. 10, a power path 260provides for an engine drive for low gear, power path 262 providesengine drive for a high gear, power path 264 provides for a charge atrest mode, power path 266 provides a charge and drive mode and powerpath 268 provides a motor only drive in low gear. The various modes willnow be described with relation to FIGS. 10A-10E.

With reference first to FIG. 10A, the engine only in high gear powerpath is shown where coupler 220 is shown moving to the right along path226 such that shaft portion 104 is decoupled from shaft portion 102.Thus, power from the CVT 34 to shaft 102 provides power along power path280 to power path 282 (through gears 230, 242), through power path 284(through shaft 240), through power path 286 (through gears 246, 252),through power path 288 (through shaft 250) and through power path 290(through gears 254, 256). As mentioned above, the power through powerpath 290 provides power to both outputs of the transaxle at 80 and 86.

With reference now to FIG. 10B, the power path will be described todefine a “charge and drive mode” whereby power from only the engine 30provides input power through the low gear setting of transaxle 34. Inthis mode, coupler 220 couples together shaft portions 102 and 104 andgear 242 is moved to the right as viewed in FIG. 10B to decouple gear242 from gear 230. Thus power moves along power path 300 (through shaftportions 102 and 104) to power path 302 (through gears 232, 244),through power path 304 (through shaft 240), and then through power paths286, 288 and 290 as described above. As shown in this mode in FIG. 10B,power is also provided to motor/generator 60 (in the generator mode)through power path 301 to charge the batteries 70.

With reference now to FIG. 10C, a “full performance” mode is shown whereinput may be received from both the engine 30 and the motor/generator 60where the power path is virtually identical to that shown in FIG. 10B,with the exception that a power path 310 is also provided frommotor/generator 60 through shaft 104. The power path therefore includesinput power paths 300 and 310 which couples to power paths 302, 304,286, 288 and 290.

With reference now to FIG. 10D, an electric only “stealth” mode is shownwhere coupler 220 is moved to the left as viewed in FIG. 10D to aposition to decouple shaft portion 102 from shaft portion 104. Thus, themotor provides input power along power path 312 (through shaft 104) topower path 314 (through gears 232, 244), along power path 316 (throughshaft 240), through power path 318 (through gears 246, 252), throughpower path 320 (through shaft 250) and through power path 322 (throughgears 254, 256).

With reference now to FIG. 10E, a “charge at rest” mode is shown wherecoupler 220 couples together shaft portions 102 and 104 and where gears242 and 244 are moved to the right as viewed in FIG. 10E to decouplethem from their corresponding gears 230 and 232 such that only the shaftportions 102, 104 are driven and shafts 240 and 250 remain idle. In thismode, the vehicle is not moving and therefore at rest and only thegenerator portion of the motor/generator 60 is utilized for rechargingthe batteries 70.

With reference now to FIGS. 11-16G, a second embodiment of hybriddrivetrain will be described. With reference first to FIGS. 11-15, ahybrid drive is shown at 416 which is similar to the hybrid drive 16described above. Hybrid drive 416 includes engine 430, transaxle 434,motor/generator 460, batteries 470, motor controller 474, transaxleoutput 478, front output 480 (FIG. 13), drive shaft 482, front finaldrive 484 and front output 486. The difference in the embodiment of FIG.11 from that of FIG. 2 relates to the manner in which motor/generator460 is coupled to the transmission 434. In this embodiment,motor/generator 460 is coupled to the transaxle 434 by way of a belt 490and pulleys or sheaves 492, 494 (FIG. 14) which provides power into thetransaxle as described herein. As shown in FIG. 12, hybrid powertrain416 is packaged in the rear frame portion 48 in much the same manner asdescribed above with respect to hybrid powertrain 16. Motor 460 iscoupled to transmission 434 by way of mounting assembly 520, as shownbest in FIGS. 14 and 15.

With reference now to FIGS. 16-16G, the operation of the hybridpowertrain 416 will be described in greater detail. With reference firstto FIG. 16, transmission 434 includes an input shaft 502 which is asolid shaft having gears at 630 and 632. A second shaft 540 is includedwhich includes gears 642 and 644 which mesh with gears 630 and 632 onshaft 502, respectively. Gear 642 may be moved laterally out of meshingengagement with gear 630 by movement in the direction of arrow 648 whilegear 644 may be moved into and out of meshing engagement with gear 632along movement according to arrow 651. Shaft 540 further includes athird gear at 646 which couples with gear 652 on shaft 650. A clutch 620moves laterally in the direction of arrow 626 which moves gear 652 intoand out of meshing engagement with gear 646. Shaft 650 further includesa gear 654 which is in meshing engagement with gear 656. It should beappreciated that gear 656 provides the output to transaxle outputs 478and 480 (FIG. 13). As with hybrid drive 16, hybrid drive 416 hasmultiple modes of operation.

With reference first to FIG. 16A, a “charge and drive” mode in high gearis shown where power into shaft 502 from CVT 34 provides power alongpower path 700 (through shaft 502) to power path 702 (through gears 630,642) along power path 704 (through shaft 540) to power path 706 (throughgears 648, 652) to power path 708 (through shaft 650) to power path 710(through gears 654, 656). At the same time as shaft is powered by inputto shaft 502, a power path 712 is provided which couples to sheave 492which powers sheave 494 through belt 490. This provides charging ofbatteries 70 while the motor/generator 460 is in the generator mode. Inthis mode, gear 644 moves in the direction of arrow 651 to disengagefrom gear 632.

As shown in FIG. 16B, a “charge and drive” mode can also be utilized inthe low gear whereby power from CVT to input shaft 502 provides a powerpath 720 (through shaft 502) to power path 722 (through gears 632, 644)which provides input to shaft 540 providing a power path 724 (throughshaft 540) to power path 726 (through gears 648, 652) to power path 728(through shaft 650) and then to power path 730 (through gears 654, 656).At the same time power is provided to shaft 540, a power path 732 isprovided (through shaft 540) to power path 714 provided by the belt 490driving sheaves 492 and 494. In this mode, gear 642 moves in thedirection of arrow 648 to disengage from gear 630.

With reference now to FIG. 16C, a “full performance” mode is shown in alow gear, which is substantially similar to the embodiment of FIG. 16B,with the exception that power is provided from the motor/generator 460to shaft 540 through power path 740 such that the motor/generator 460 isoperating in the motor mode and assisting in the driving of shaft 540.In a similar manner, and as shown in FIG. 16D, a “full performance” modeis shown in high gear which is substantially similar to that describedwith respect to FIG. 16A, with the exception that power is provided frommotor/generator 460 through power path 740 to drive shaft 540.

An electric only drive mode is shown in FIG. 16E where gears 642 and 644are disengaged such that power from only motor/generator 460 in themotor mode is driven to shaft 540 through power path 750 to power path752 (through shaft 540) to power path 754 (through gears 648 and 652) toshaft 650 through power path 756 and to power path 758 (through gears654, 656).

Finally and with respect to FIG. 16F, a “charge at rest” mode is shownthrough the low gear such that input from the CVT to shaft 502 providesinput to power path 770 (through gears 632, 644) to power path 772(through shaft 540) and through power path 774 (through belt 490 andsheaves 492, 494). It should be appreciated that clutch 620 in thisconfiguration moves gear 652 in the direction of arrow 626 to take gear652 out of meshing engagement with gear 648, such that shaft 650 is notrotated. Gear 642 is also disengaged from gear 630 having been moved inthe direction of arrow 648.

A similar charge at rest mode is shown in FIG. 16G, through the highgear whereby input power to shaft 502 provides input through power path780 (through shaft 502) to power path 782 (through gears 630, 642) topower path 784 (through shaft 540) and to power path 786 (through belt490 and driving sheaves 492, 494). As in the embodiment of FIG. 16, gear652 is moved by clutch 620 out of meshing engagement with gear 648 bymoving gear in the direction of arrow 626. Gear 644 is also disengagedfrom gear 632 having been moved in the direction of arrow 651.

Finally, a third embodiment of powertrain could be provided where amotor/generator is mounted on the same side as the CVT, where themotor/generator is coupled to the driven CVT pulley. This could be doneby a belt and sheaves for example, where one sheave is coupled to themotor/generator (similar to the embodiment shown in FIG. 14) and theother sheave is coupled to the CVT pulley shaft.

With respect to FIG. 17, a control system 800 of vehicle 10 may beincluded to control operation of any of the powertrain assembliesdisclosed herein. Control system 800 includes a hybrid control unit(“HCU”) 801 which is operatively coupled to various control unitsthrough a communications network or device, such as a CAN bus 802. Forexample, HCU 801 may be operatively coupled to an engine control unit(“ECU”) 804, a motor control unit (“MCU”) 806, and a transmissioncontrol unit (“TCU”) 808. It may appreciated that ECU 804 may be thesame as engine control unit 74 of FIG. 2 and MCU 806 may the same asmotor controller 474 of FIG. 12. In this way, various components of thepowertrain assemblies disclosed herein may be controlled by individualcontrol units or controllers. However, in other embodiments, the variouscontrollers or control units may be defined as a single controller orcontrol unit but separated by software for individual control of themotor, engine, batteries, and other powertrain components.

Referring still to FIG. 17, HCU 801 is configured to receive inputs orrequests from other vehicle components, defined as driverinputs/requests 810. For example, various driver inputs/requests 810 maybe provided from the accelerator pedal, the gearbox, and the clutch. Inone embodiment, driver inputs/requests 810 may include an input to theaccelerator pedal, a requested gearbox position, and a requested drivingdirection (e.g., forward or reverse).

Control system 800 may be used to provide various modes for operatingvehicle 10. In one embodiment, vehicle 10 is configured to operate in aDownhill Speed Control Mode, a Hill Hold Control Mode, a Snow PlowControl Mode, and an Electric Drive-Away Control Mode, as disclosedherein.

Downhill Speed Control Mode

When vehicle 10 operates in the Downhill Speed Control Mode, vehicle 10is driving downhill and, due to gravity, the velocity of vehicle 10 canincrease. Motor/generator 60, 460 may assist with braking vehicle 10 toa specific speed without applying the mechanical brake. Moreparticularly, a negative torque may be applied relative to the directionof driving to maintain a constant velocity of vehicle 10 without theneed to apply the mechanical brake when driving downhill. Additionally,when in the Downhill Speed Control Mode, battery 70 may be recharged.For example, motor/generator 60, 460 may be used as a generator torecharge battery 70 when the charge on battery 70 is less than 100%.

As shown in FIG. 18, when in the Downhill Speed Control Mode, controlsystem 800 may utilize at least one look-up table to determine thetorque requested on motor/generator 60, 460. More particularly, at 812,the accelerator pedal input is determined and compared to theregenerative threshold at 814. The comparison of the accelerator pedalinput to the regenerative threshold leads to a true/false path at 816,where a zero input at 818 may be provided or an output from 826 beprovided, in order determine the regenerative torque. More particularly,at 816, there is a determination that, if the input is true, then theoutput is equal to the first output; however, if the determination isfalse or not true, then the output is equal to the second output. Forexample, as shown at 820, when the RPM of motor/generator 60, 460 isless than zero, the regenerative torque is determined following 821 andused for generating the torque request on motor/generator 60, 460 at822. Again, at 821, if the determination of the input is true, then theoutput is equal to the first output; however, if the determination at821 is that the input is false or not true, then the output is equal tothe second output. As such, if the state-of-charge on the battery is ina predetermined range for regeneration, the accelerator pedal input isbelow the regenerative threshold, and the RPM of motor/generator 60, 460is above a threshold, then the braking torque will increase to a maximumvalue. However, if the RPM of motor/generator 60, 460 decreases to avalue below the regenerative threshold, the regenerative torque will beincreased to zero to bring vehicle 10 to a smooth stop. In each state,if the accelerator pedal input exceeds the minimum regenerativethreshold, vehicle 10 will return an idle state.

Additionally, as shown at 823, the absolute value of motor/generator 60,460 is used with respect to a look-up table at 824 to determine a signalor input, as shown at 826, in order to arrive at the true/false path at816. Also, referring still to FIG. 18, at 828 shows that the acceleratorpedal is sealed from 1-0 for the range of 0 to the regenerativethreshold in order to arrive at the signal(s) or input at 826. In may beappreciated that 826 in both FIGS. 18 and 19 denote a multiplication ofthe two input signals.

With respect to 830, the accelerator pedal input is compared to alook-up table at 832 to determine the acceleration torque. Theacceleration torque is then used to determine the torque requested formotor/generator 60, 460, as shown at 822. It may be appreciated that,outside of the state flow shown in FIG. 18, the regenerative torque willbe scaled to the range of the accelerator pedal between zero and aminimum pedal regenerative input to allow the driver to actively controlthe braking torque over the throttle accelerator pedal. Theseregenerative controls of vehicle 10 may be used to request aregenerative torque or an acceleration torque from motor/generator 60,460.

Hill Hold Control Mode

When vehicle 10 operates in the Hill Hold Control Mode, control system800 prevents vehicle 10 from rolling backwards without applying thebrake pedal when stopping on steep grades of terrain. More particularly,motor/generator 60, 460 may be used to fully stop vehicle 10 or allowvehicle 10 to roll backwards at a controlled and slow speed.

With respect to FIG. 19, the open-loop, look-up table approach of FIG.18 also may be used during the Hill Hold Control Mode. If vehicle 10tends to roll down hill and the accelerator pedal position is zero, thenthe acceleration torque also will be zero. However, becausemotor/generator 60, 460 will start to spin, the braking torque, as shownas determined following 826, will increase and slow down vehicle 10.

Snow Plow Control Mode

To perform various tasks, such as plowing snow or allowing for a load atthe front end of vehicle 10, the operator desires to have the ability toquickly change between forward and reverse. Additionally, when in theforward mode, vehicle 10 must be capable of pushing or otherwisehandling heavy loads. When in the Snow Plow Mode, vehicle 10 is drivenforward using engine 30, 430. Engine 30, 430 may be used alone or incombination with motor/generator 60, 460. When vehicle 10 is driven inreverse, only motor/generator 60, 460 is used and engine 30, 430 idles.The driver has the full power and torque available while driving forwardand has the option to quickly change to reverse without any mechanicalshifting required. More particularly, the transmission position may bein “LOW” in both driving directions, thereby allowing this change indirections to occur without any mechanical shifting. As such, whenvehicle 10 is driving in the forward direction, engine 30, 430 providestorque while motor/generator 60, 460 provides a positive torque;however, when vehicle 10 is driving in the reverse direction, engine 30,430 idles while motor/generator 60, 460 provides negative torque. It maybe appreciated that the forward/reverse selection input may be anyswitch, treadle pedal, or other mechanism which provides an electricalsignal or CAN message for the different requested states or drivingdirections.

Electric Drive-Away Control Mode

To allow for improved low-speed drivability and maneuvering, controlsystem 800 may allow vehicle 10 to be driven in an Electric Drive-AwayControl Mode. In this mode, when vehicle 10 is operating as a hybridvehicle, whereby both engine 30, 430 and motor/generator 60, 460 areused to drive vehicle 10, vehicle 10 may initially start moving usingonly motor/generator 60, 460 to allow for smooth operation of vehicle 10at low speeds. When the speed of vehicle 10 increases to a predeterminedthreshold and the clutch engages such that both motor/generator 60, 460and engine 30, 430 are used to drive, vehicle 10 then operates at fullperformance.

More particularly, as shown in FIG. 20, when at 840 in a low-speeddrive-away/maneuvering operation of vehicle 10, only motor/generator 60,460 is used and is set to a torque control mode. As the speed of vehicle10 increases above a predetermined threshold, the speed of engine 30,430 increases, as shown at 842, and the engine speed may equal the speedof the driven clutch. Specifically, at 842, the speed of the secondaryclutch of the CVT is monitored, for example it may be known through thewheel-based speed of motor/generator 60, 460. Engine 30, 430 may beoperated in a speed-controlled mode and the speed of engine 30, 430 andthe CVT driven clutch may be synchronized. It may be appreciated thatmotor/generator 60, 460 remains in the torque-control mode at 842. Asshown at 844, for normal driving operation of vehicle 10 at speeds abovethe threshold, engine 30, 430 may be set to the torque-control mode suchthat both motor/generator 60, 460 and engine 30, 430 are in thetorque-control mode.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

1. A parallel hybrid power train for a vehicle, comprising: an engine;an electric motor/generator; a transmission having an input shaft, atleast a second shaft drivingly coupled to the input shaft, the engineand the electric motor/generator being coupled to one of the input orsecond shafts, and at least a first output, and the input shaft and thesecond shaft may be decoupled from each other during operation of theparallel hybrid power train; and a final drive assembly operably coupledto the first output, the final drive assembly being provided for drivingground engaging members of a vehicle.
 2. The parallel hybrid power trainof claim 1, wherein the engine and the electric motor/generator arecoupled to the transmission input shaft.
 3. The parallel hybrid powertrain of claim 2, wherein the engine and the electric motor/generatorare coupled to opposite ends of the transmission input shaft.
 4. Theparallel hybrid power train of claim 3, wherein the transmission inputshaft is split at a position along a length defining first and secondshaft portions, wherein the engine is coupled to an outer end of thefirst shaft portion and the electric motor/generator is coupled to anouter end of the second shaft portion.
 5. The parallel hybrid powertrain of claim 4, further comprising a coupler positioned over an innerend of the first shaft portion and an inner end of the second shaftportion.
 6. The parallel hybrid power train of claim 5, wherein thecoupler is movable along the length of the input shaft, wherein, when ina first position, the first and second shaft portions are coupledtogether, and when in a second position, the first and second shaftportions are decoupled from each other.
 7. The parallel hybrid powertrain of claim 6, wherein when the coupler is in the first position, theengine may drive the input shaft and the electric motor/generator mayoperate in a motor mode and drive the input shaft.
 8. The parallelhybrid power train of claim 6, wherein when the coupler is in the firstposition, the engine may drive the input shaft and the electricmotor/generator in a generator mode.
 9. (canceled)
 10. The parallelhybrid power train of claim 1, wherein when the coupler is in the firstposition, the input and second shafts may be decoupled from each otherand the engine may drive the electric motor/generator in a generatormode.
 11. The parallel hybrid power train of claim 6, wherein when thecoupler is in the second position, either the engine or electricmotor/generator may drive the input shaft.
 12. The parallel hybrid powertrain of claim 1, wherein the coupling between the input and secondshaft is by way of gears.
 13. The parallel hybrid power train of claim12, wherein a first gear is positioned on the first shaft portion and asecond gear is positioned on the second shaft portion.
 14. The parallelhybrid power train of claim 13, wherein a third gear is positioned onthe second shaft and in engagement with the first gear.
 15. The parallelhybrid power train of claim 14, wherein a fourth gear is positioned onthe second shaft and in engagement with the second gear.
 16. Theparallel hybrid power train of claim 15, wherein one of the third gearor fourth gear is laterally movable along the second shaft and out ofengagement with the first or second gear.
 17. The parallel hybrid powertrain of claim 1, further comprising a third shaft coupled to the secondshaft.
 18. The parallel hybrid power train of claim 1, wherein theengine is coupled to the transmission input shaft and the electricmotor/generator is coupled to the second shaft.
 19. The parallel hybridpower train of claim 17, wherein the coupling between the input andsecond shaft is by way of gears.
 20. The parallel hybrid power train ofclaim 18, wherein first and second gears are positioned on the inputshaft.
 21. The parallel hybrid power train of claim 19, wherein thirdand fourth gears are positioned on the second shaft and in engagementwith the first gear and second gears.
 22. The parallel hybrid powertrain of claim 21, wherein one of the third gear or fourth gear islaterally movable along the second shaft and out of engagement with thefirst or second gear.
 23. The parallel hybrid power train of claim 18,further comprising a third shaft coupled to the second shaft.
 24. Theparallel hybrid power train of claim 22, further comprising a thirdshaft coupled to the second shaft.
 25. The parallel hybrid power trainof claim 24, wherein a fifth gear is positioned on the second shaft anda sixth gear is positioned on the third shaft and the fifth and sixthgears are in meshing engagement.
 26. The parallel hybrid power train ofclaim 25, wherein the sixth gear is laterally movable along the thirdshaft and into and out engagement with the fifth gear.
 27. The parallelhybrid power train of claim 18, wherein the engine drives the inputshaft and the electric motor/generator operates in a motor mode anddrives the second shaft.
 28. The parallel hybrid power train of claim18, wherein the electric motor/generator operates in a generator modeand the engine drives the input shaft and the electric motor/generator.29. The parallel hybrid power train of claim 23, wherein the second andthird shafts may be decoupled from each other.
 30. The parallel hybridpower train of claim 29, wherein when the input and second shafts aredecoupled from each other the engine may drive the electricmotor/generator in a generator mode with no power to the first output.31. The parallel hybrid power train of claim 1, wherein the second shaftis axially offset from the input shaft.
 32. The parallel hybrid powertrain of claim 31, wherein the second shaft is unaligned with the inputshaft.
 33. The parallel hybrid power train of claim 1, wherein the inputshaft extends in an axial direction and a radial direction, and thesecond shaft is spaced apart from the input shaft in the radialdirection and is parallel to the input shaft in the axial direction. 34.The parallel hybrid power train of claim 1, wherein the transmission isa shiftable transmission defined by gears.
 35. A parallel hybrid powertrain for a vehicle, comprising: an engine; an electric motor/generator;a transmission having an input shaft, at least a second shaft drivinglycoupled to the input shaft, the engine and the electric motor/generatorbeing coupled to one of the input or second shafts, and at least a firstoutput; a final drive assembly operably coupled to the first output, thefinal drive assembly being profiled for driving ground engaging membersof a vehicle, wherein the transmission input shaft is split at aposition along a length defining first and second shaft portions, andthe engine is coupled to an outer end of the first shaft portion and theelectric motor/generator is coupled to an outer end of the second shaftportion; and a coupler positioned over an inner end of the first shaftportion and an inner end of the second shaft portion, wherein thecoupler is movable along the length of the input shaft, wherein, when ina first position, the first and second shaft portions are coupledtogether, and when in a second position, the first and second shaftportions are decoupled from each other.
 36. A parallel hybrid powertrain for a vehicle, comprising: an engine; an electric motor/generator;a transmission having an input shaft, at least a second shaft drivinglycoupled to the input shaft, the engine and the electric motor/generatorbeing coupled to one of the input or second shafts, and at least a firstoutput, wherein the transmission input shaft is split at a positionalong a length defining first and second shaft portions; and a finaldrive assembly operably coupled to the first output, the final driveassembly being profiled for driving ground engaging members of avehicle, wherein the coupling between the input and second shaft is byway of gears, and a first gear is positioned on the first shaft portion,a second gear is positioned on the second shaft portion, a third gear ispositioned on the second shaft and in engagement with the first gear, afourth gear is positioned on the second shaft and in engagement with thesecond gear, and one of the third gear or fourth gear is laterallymovable along the second shaft and out of engagement with the first orsecond gear.